Radiator fluid: protect your engine from freezing and overheating with the right mixture of automotive fluids.

Radiator fluid (common name, “antifreeze”) is a mixture of chemicals that cool the engine and protect and lubricate internal components such as water pumps and radiators; when properly mixed with water, it is called “coolant.”

Unlike water, a 50/50 mixture of water and antifreeze will not freeze at even the coldest temperatures we may encounter. Freezing would damage your engine (visualize what happened when you forgot that bottle of Pepsi you put in the freezer for a quick chill-down!) When water (or Pepsi) freezes, it expands, and that can cause engine damage (especially if you have Pepsi in your engine).

Engine protection tips

The correct 50/50 mix of water and antifreeze is best at protecting your engine from freezing AND overheating. Water alone will freeze when the temperature drops to 32 degrees or lower. So, when the red warning light comes on signaling that your engine is overheating while you are driving to work on a frigid morning with snow flying, you are understandably puzzled. After all, it’s freezing outside! Ah, remember that balmy summer Saturday when you “temporarily” put water in the radiator? The liquid that is supposed to be circulating, picking up the heat of combustion and carrying that heat to the radiator where it is released into the atmosphere, is not circulating, because it is water, and has frozen into clumps of ice in the engine.

As with everything else, too much of a good thing can be, well, just that, too much. Pure radiator fluid, just like water alone, is not better than the recommended 50/50 mixture because, by itself, radiator fluid cannot carry heat as well, and that means overheating in the summer. So just do it right (or have the shop do it, because they know how).

While the “anti-freeze” properties of car coolant are never lost (if that is what you are testing for), the effectiveness wears out, as corrosion inhibitors and lubricants become depleted, and the car coolant accumulates dirt and wear particles. That is when corrosion can occur, restricting radiator flow and performance; engine damage can begin. The best defense against this is a good offense, so change the coolant before it is unable to protect your cooling system. Start by checking your owner’s manual for the manufacturer’s recommendation, or consult your trusted mechanic. He will offer to perform some quick and free tests of the chemical properties of your car coolant.

What’s the best for engine protection? Green, red or orange radiator fluid?

What gives? My Dad and I have always used the pretty fluorescent green stuff…but the stuff I can see in my vehicle’s overflow bottle is red. Can I use the green Prestone I bought from the car parts store? In most cases, the answer is “no.” Modern vehicles come with an array of different coolants, and most of them are not compatible. There is the original radiator fluid (like what you picked up),; there are organic, long-lasting antifreezes; and there are even synthetic antifreezes. So you need to start with what is the right one for your vehicle. Mixing them can cause catastrophic failure.

Doing it yourself, by opening the radiator petcock or removing the lower radiator hose to drain the automotive fluids after the engine has cooled, even if you use a garden hose to try to flush it, is not very effective in removing dirt, debris and even all of the old, corrosive antifreeze (you can’t get to what is in the cooling passageways in the engine block or in the heater core easily). And that does not even cover disposing of the poisonous old automotive fluids; you can’t just flush it down the driveway and into the storm sewer!

Shops have equipment they can connect to your vehicle to effectively flush and clean your engine and heater core, and then “exchange” the old fluid with the proper fresh mix of water and radiator fluid. They will also make sure there are no air bubbles (like a baby, the system may need to be burped) that would prevent a complete fill of car coolant. They will be checking the thermostat for proper operation, and will advise you on the condition of your radiator and heater hoses and drive belts.

And when that is done, congratulate yourself on being smart about engine protection – and maybe even saving yourself the unbelievable inconvenience of a breakdown!

Find the info you need about more important automotive fluids here!